Automatic railway block signaling system



NOV. 28, D. N HY 1,936,705

AUTOMATIC RAILWAY BLOCK SIGNALING SYSTEM Filed April 19, 1927 I Invenxfo flurry I. 7 r

Patented Nov. 28, 1933 UNITED STATES AUTOMATICRAILWAY BLOCK SIGNALING SYSTEM Harry D. Abernethy, Cleveland, 0hio,'assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application April 19, 1927. Serial No. 184,884-- 8 Claims.

This invention relates to a novel and improved automatic railway block signaling system 'intended to dispense'withall movable parts usually employed in connection with such systems.

The prime object of this invention is to provide novel means constituting electrical controlling circuits whereby railway block signals are successfully and practically operated without the use of relays, movable contacts, or other movable parts by direct and alternating currents.

Another object of the invention is to so construct this signaling system that the controlling electrical circuits will successfully operate suitable or desirable railway block signals by a combination of alternating and direct or unidirectional current, and at the same time dispensing with all movable parts in connection therewith.

In the present art of railway block signaling systems usually employed, use is made of relays, so-called, which are equipped with coils for receiving electrical energy from one source and controlling electrical energy from anothersource by moving one or more contacts from one position of engagement to another by means of the magnetic influence set up in the coils. These relays have to be carefully constructed and frequent tests made of them to insure that the physical movement of the armature and contacts are free and that the contacts have proper adjustment, clearance, etc., while my invention is so devised as to dispense with all movement of parts and obtain the same signal operation as is attained by relays with their movable armatures and contacts.

The foregoing and such'other objects as may appear from the ensuing description are accomplished by the construction, arrangement, location and combination of the several parts hereinafter more fully described, illustrated by-the accompanying drawing, and particularly pointed out in the claims appended hereto, it being understood that slight changes in the precise proportions and minor details of' construction may be resorted to without departing from the spirit or sacrificing any of the advantages of the invention.

In the accompanying drawing forming a part of this specification it will be seen that.

Figure Us a diagrammatic View showing means embodying the basis of this invention, and

Figure 2 is a diagrammatic view showing the invention as applied in connection with automatic railway block signaling.

In the embodiment of my invention as illustrated in Fig. 1, the letter Adesignates an iron C and E.

frame, preferably constructed of thin strips of iron, or laminations with openings B formed therethrough for the winding of wire on the portions C, D and E; the windings to be formed .of

a suitable number of turns, such as may-be required for the particular work to be done. The winding on portion D is connected to some ,desirable source of power, as represented at F which may be a continuous or pulsating electrical current, and controlled by some suitable means such as a switch G and in this case is the controlling circuit, although the windings C and E may be used as the controlling circuit.

The windings on portions .0 and Eare also connected to some source of energy such as H which must be an alternating current, and are so connected together that the direction of magnetic flux set up in the iron frame A by current from alternator H through the windings is the same, and therefore the current is limited to a very small value of self-induction, exactly as in a transformer. These lines of force .or magnetic flux are represented by the arrows shown in Fig.1. The windings on portionC and E are of the same number of turns.

When switch G is closed direct or unidirectional .current'from the source F flows through the winding on portion 50 and the magnetic flux, or lines of force, set .up .by this current in the winding has the .efiect of increasing flux in the iron frame to such value that .the limiting effect of self-induction in coils C and E is .destroyed, that is, the iron in the frame is approaching -magnetic saturation. The current is permitted together 'noelectro-motive force is induced in coil D, and if .wire J and :K areconnected together, as shown by the dotted line in Fig. 1, no change will occur in the circuit through coils The functions of the coils D, C and E may be reversed-that is, C and E maylbe used as the controllingcoils and D the controlled circuit. Also more than one circuit may be controlledby using separate coilor coils foreach circuit.

Now by reference to Fig.2 of thedrawing the following .willdescribe how themeans shown in Fig. 1 is adapted to control automatic, signals for railways. p

The letters It and R" representthe railsof a railway bonded together at their ends and insulated at each signal, as shown at U, U, U". Current is supplied to the rails at the outgoing end of a block section and is furnished through wires 10, 11, 12 and resistance 13, which resistance is used to adjust current tothe rails from some source of direct, unidirectional or pulsating current, not shown. The entrance end of the block section is connected by means of the wires 14 and 15 to coil D which functions as heretofore referred to in connection with Fig. l, coils C, D and E being part of the apparatus as explained.

With a train in the block as at M this track current referred to in the preceding paragraph will be shunted out of the coil D and permit the current from secondary coil 16 of transformer 3 to flow through wire 17, and resistance 18, and wire 19, through the filament of redlamp 1' causing filament to glow and produce a red light or signal warning following trains of presence in the block of a train at M, through wire 20 returning to secondary coil 16. The circuit of the red lamp 1' is a simple circuit starting from sec ondary of transformer 3, whose primary 5 is energized from power lines 6 and '7 throughwires .8 and 9. Starting at coil 16 circuit is through wire 1'7, resistance 18, wire 19, filament of lamp 1", wire 20 back to secondary coil of transformer. This circuit includes part of secondary coil of transformer 3 and a certain current flows due to voltage impressed on secondary coil by primary coil 5. No current can flow through wire 21 coil E and C because coil D is not energized by current from track through wires 14 and 15 due to wheels and axles of train shunting current from this coil.

When the train passes from M to the next block, as shown at N,.current will flow from secondary coil 16, through wire 17, portion of resistance 18, wire 21, through coil E, coil C, wire 23, wire 25, filament ofyellow lamp 2', wire 26, secondary coil 27, to secondary ,16.

The flow of current from the source of power at the outgoing end of the block through rails and coil D at the incoming endof block permits the passage of the above-described current. This flow of current through portion of resistance 18' causes reduction in current and voltage applied to the circuit for the red lamp of suflicient amount to allow the filament of the red lamp to cool of! and show no light. v The current flow through the yellow lamp filament hereinbeiore described is of suflicient value,

.. due to increased voltage added to, the circuit by the secondary coil 27, to cause the filament to glow and display a yellow light to approaching trains. This yellow light indicates to trains that the immediate blockzahead is clear.

The same effect and circuits herein described in connection with the operation of signal at U is ,present. at signal at U and U", and as many succeedingblock sections as may be desired and constitute my improved automatic block system.

t T is shown a circuit which can be used to control any additional signal indication which may be desired, or can be used to control any other apparatus, such as an alternating current relay.

controlling current for motors, etc. at remote points, and it will be readily obvious that the signals do not have to be necessarily of the electric light type, but may be of the motor type. I

It will be understood that the device such as illustrated in Fig. l, which shows a type of transformer construction, is not used as a transformer, but is employed as what may be properly termed a current choking apparatus.

Having thus described my invention what I claim and desire to secure by Letters Patent is:

l. A railway signaling system of the character described, comprising means by which a direct or unidirectional electrical current in the track rails controls a signal operating current by means of an electro-magnetic translating device, all parts of said system being stationary.

2. An automatic block signaling system for railways, comprising alternating current means for displaying signal indications, resistances used in connection with said indications for dividing the current, direct or unidirectional current meansfor controllng the alternating electrical current means to display proper signal indication, all of the parts of said system being stationary.

3. An automatic block signaling system for railways, comprising means formed of stationary iron cores and coils to control alternating current signal indications, means for choking the alternating electrical current in connection with said signal indications, and means whereby a direct or unidirectional current controls said choking of said alternating electrical current for operating a signal. Y

4. In combination, a section of railway track, a source of current connected with the rails of said section, a device having a magnetizable core provided with a winding controlled by currentreceived from the rails of said section and in turn acting to vary the permeability of at least a portion of said core, an output circuit including a source of alternatingcurrent and a winding of said device for varying the amount of current flowing in said circuit in accordance with variations of the permeability of said core caused .1 20 by said control winding, and a signal for said section controlled by said output circuit.

5. In combination, 'a section of railway track,

a source of current connected with the rails of said section, a device having a magnetizable core provided with a winding controlled by current received from the rails of said section and in turn acting to vary the permeability of at least a portion of said core, a signal for said section, and. a control circuit for said signal including a-139 source of alternating current and having its impedance varied in response to. variations of the permeability o'f'said core.

6. In combination, a section of railway track,

a source of current connected with the rails of said section, a device having a magnetizable core provided with a winding controlled by current received from the rails of said section and in turn acting to vary the permeability of at least a portion of said core, a signal for said section -mo and a control circuit for said signal including a source of alternating current and a winding of said device the impedance of which is varied in response to variations of the permeability ofsaid core.

7. In combination, a section of railway track, a source of current connected across the-rails of said section, a device located in the trackway and having a magnetizable core provided with a winding which is connected across the rails of 1150 said section and which serves to vary the permeability of at least a portion of said core in accordance with variations of the current flowing in the track rails, a signal located in the trackway for governing trafiic through said track section, and a circuit including a winding linking said core and controlling the signal in response to variations in the permeability of said core.

8. In combination, a section of railway track, a sourse of current connected across the rails of said section, a device located in the trackway 

